Glomerular filtration rate after liver transplantation with a low-dose cyclosporin protocol

Cyclosporin nephrotoxicity is a well-known complication in organ transplantation. In successful liver transplantation, a moderate degree of renal impairment is accepted. Whether this impairment is continuously progressive, stabilizes with time, or is reversible is not known. We have prospectively evaluated the glomerular filtration rate (GFR) using ⁵¹CrEDTA plasma clearance in 29 liver transplant patients (11 males and 18 females) with a mean age of 49 years (range 22–62 years). The ⁵¹CrEDTA plasma clearance measurements were performed preoperatively and at 3, 6, 12, 24, and 36 months after the liver transplantation. All but six patients were given sequential, quadruple drug therapy with antithymocyte globulin, azathioprine, steroids, and cyclosporin. Intravenous cyclosporin was avoided and oral cyclosporin started when renal function was stable. Cyclosporin was started in a dose of 8 mg/kg body weight, aiming at whole blood trough levels (specific monoclonal technique) of 200 g/l in the postoperative period; thereafter, the dosage was rapidly tapered down, aiming at whole blood trough levels of less than 100 g/l at 3 months (1.5–2 mg/kg body weight). From a mean preoperative GFR of 89±3 ml/min per 1.73 m², all patients declined in renal function after transplantation to a mean of 64±4 ml/min per 1.73 m² 3 months after transplantation, and starting in the 3rd month the renal function was stable at about 70% of the preoperative value. No correlations were found between cyclosporin weak level or accumulated cyclosporin dose and renal impairment. We conclude that liver transplantation with cyclosporin immunosuppression will induce renal impairment even if cyclosporin blood levels are carefully monitored and kept low. However, with a low-dose regimen, a progressive decline can be avoided.